Steel corrugated steel pipes for highways, generally in the shape of a circle, an ellipse, a horseshoe or an arch, etc., all adopt an arc-shaped plate structure, so as to ensure the strength of the overall structure by utilizing the pipe-soil joint stressing principle when the structure is stressed. Regardless of whether the unit plates for constituting the unit pipe sections have the same center, the same radius, or multiple centers and multiple radii, the circumferential connection of the unit plates adopts an arc-shaped transition instead of connection by means of forming an obtuse angle between the plates. As shown in FIG. 16 to FIG. 18, in ordinary ducts of which the cross-sectional shape is generally circular, elliptical, horseshoe-shaped or arched, etc., the ordinary arc-shaped transition pipe culvert has the defects of low utilization ratio of the internal clearance, a great waste of space and high top chord height, result in increasing the earthwork excavation amount. However, in some cases where there is a specific requirement for the utilization ratio of the internal clearance of the duct, such as the corridor structure of the urban underground integrated pipe gallery and the culvert allowing passage of vehicles therefrom, it is necessary to make the cross section an approximately rectangular box shape to ensure the utilization ratio of clearance of the duct; and it is also necessary to use the pipe-soil joint stressing principle to ensure the overall strength, facilitate construction and accelerate the construction progress, so the traditional cross-section form and connection method cannot meet the requirements.
Therefore, it is urgent to solve the above technical problems.